Refrigeration unit



Filed Dec. 8, 1941 -66@ sec fi 3 X kl s w Q u w 5 a H wi l New 3 m a w 55 A g Gui 3 a N\ R.. mwww d J M 5 A m Patented Sept. 4,

Application December 8, 1941, Serial No. 422,089

2 Claims.

This invention relates to a refrigeration unit and more particularly to a portable refrigeration unit driven by an internal combustion engine which is particularly useful for refrigerating the storage compartments of moving vehicles, such as motor trucks, trailers and railway cars. In this type of refrigeration unit it is desirable that the evaporator should be defrosted quickly with substantially no rise in the temperature within the refrigerated compartment.

It is the object of this invention to produce a I refrigeration unit driven by an internal combustion engine which can be quickly defrosted and returned to the refrigerating cycle with no substantial change in the temperature within the refrigerated compartment.

The drawing shows a diagrammatic lay-out of the refrigerating unit.

Referring more particularly to the drawing there is shown an internal combustion engine I with an exhaust line 2 and an exhaust shy-pass line I controlled by valves 4 and U which are connected together by levers 6 and I and link 8 so that valves 4 and open and close simultaneously.

The refrigerating unit comprises a compressor 9, condenser l0, receiver tank ll, expansion valve l2 and evaporator IS. A pipeline l4 connects the compressor with the condenser. Pipe line It connects the condenser with the receiver I i. Line It connects the receiver l I with the expansion valve l2. Line I! connects the expansion valve I 2 with the evaporator l3 and line I 8 connects the evaporator with the intake port of the compressor 9.

The engine I drives a generator is, the compressor 9 and the condenser fan 2| by means of a belt and pulley arrangement generally designated 20. The generator drives an electric motor 22 which drives the evaporator fan 22. Line l4 fin the pressure line whereas line It is the suction A by-pass valve 24 controlled bysolenoid 25 is placed in line l4. A by-pass valve 25 controlled by solenoid 21 is placed in line l6 and a by-pass valve 28 controlled by solenoid 29 is inserted in by-pass line 20. By-pass valve 24 controls bypass line II which runs between line It and line I 4. vBy-pass valve 26 controls by-pass line 32 which runs from line I! to line I! to by-pass expansion valveJj; By-pass valve 28 is positioned in line 20 so that the suction line ll can by-pass expansion valve 22. Line II is coiled around the exhaust by-passline l to effect heat exchange between the gases in line It and the exhaust gases of the engine I at the proper time, as outlined below.

In the full line showing of the drawing the unit is operating in the refrigeration cycle, that is, the compressed refrigerant passes through line l4, solenoid valve 24 into the condenser l0, through line l5 into receiver ll, thence through line l8, by-pass valve 26, expansion valve l2 into the evaporator l3 and then through line 30, bypass valve 28 and line H back into the compressor. During the refrigeration cycle exhaust valves 4 and 5 are closed so that the exhaust gases are notpassing throughby-pass line 3 but are passing through line 2 direct to atmosphere.

when it is desired to defrost the unit, exhaust valves 4 and I are manually thrown to open position, as shown in the dotted lines, whereupon th exhaust gases are now directed through bypass line 2. As exhaust valves 4 and S are simultaneously opened, switch 25 interconnected therewith is closed thus placing battery 38 inchcuit with the solenoids 25, 21 and 29, thereby energizing these solenoids. Energization 0f the solenoids 25, 21 and :29 produces the following result: By-pass valve 24 connects line l4 with line ll' so that the compressed gases by-pass, that is, do not flow through the condenser l0 and receiver II but pass through lines 3| and ii to by-pass valve 28. By-pass valve 26 is now turned to the dotted line position so that the gases bypass expansion valve 12 and pass directly through lines 32 and I1 into the evaporator l3. By-pass valve 28 has now shut off line 30 so that the gases pass from the low side of the evaporator through expansion valve 33 where they are further expanded to absorb heat and then pass through line It! and the coil about the hot exhaust by-pass line 3 where they are heated and expanded preparatory to passing into the compressor 9. It is evident that the heated gases upon being compressed pick up further heat preparatory to being passed through the evaporator l2 and thus speedily defrost the evaporator. Check valve 31 per-' mits the gases toflow only in the direction of the arrow and thus prevents the gases from flowing from line 3| back into the receiver II and condenser In.

As soon as the unit is defrosted, valves 4 and' I are again operated to shut off the by-pass line 3 and open switch 35 which breaks the circuit between the battery 26 and the solenoids 25, 21

*and 29 whereupon the by-pass valves. 24, 26 and 28 return to the full line position shown in the drawing and the refrigeration cycle begins.

I claim:

1, In a refrigerating system comprising a compressor 8, a condenser I0, an evaporator I3, 2. line I 4connecting the high side of the compressor with the condenser, a line II, I8, i1 connecting the condenser with the evaporator, a suction line I8 connecting the evaporator with the low side-o! the compressor, a first solenoid operated by-pass valve 24 connected into the line I4 between the high side of the compressor and the condenser, a by-pass line 3| forming a connection between the above said by-pass valve 24 and the said line I5, I 8, I1 between the condenser and 'the evaporator, an expansionvalve [2 in the second mentioned line I5, I6, I 'I positioned between the evaporator and the point at which the above said by-pass line 3I connects into the line I6, I8, I! between the condenser and evaporator, a second solenoid operated by-pass valve 28 in the line IS, IS, I'I running between th condenser and evaporator and positioned between said expansion valve I2 and the point at which said by-pass line 3i connects into the line I5, I6, I'l running between the condenser and the evaporator, a by-pass line 32 about said expansion valve I2, the second mentioned by-pass line 32 connecting the second mentioned solenoid operated valve 28' with the part of the second mentioned line II, I8, I1 extending from said expansion valve I2 to the evaporator. I3, an internal combustion engine for operating said compressor, an exhaust line 3 for said engine constituting a source of heat, said exhaust line being in heat I exchange relation with said line 18 connecting the evaporator with the low side of the comass-1,210

' pressor, a valv 4 for said exhaust line, said exhaust line valve 4 when closed preventing the exhaust gases from flowing through said exhaust line and when open permitting the exhaust gases to flow through said exhaust line 3, and means for coincidentally operating said solenoid by-pass valves 24, 2O toopen them into their respective by-pass lines SI, 32 and for opening said exhaust line valve 4, whereby the refrigerant may bypass the condenser IO and the said expansion valve I2 in the line II, l8, l1 running between v the condenser and evaporator'and whereby the exhaust gases may flow through the exhaust line 3 and the refrigeration system may be quickly defrosted.

2. Th combination as claimed in claim 1 including a second expansion valve 33 positioned in said suction line l8 between the evaporator I3 and the exhaust line 3 of said engine, and a third solenoid operated by-pass valve 28 in a line 30 connected into said line I8 between the evaporator and the low side of the compressor for by- JAMES J. SUNDAY. 

